The flat panel display elements possess many merits of thin frame, power saving, no radiation, etc. and have been widely used. The present flat panel display elements at present mainly comprise the Liquid Crystal Display (LCD) and the Organic Light Emitting Display (OLED).
An OLED possesses many outstanding properties of self-illumination, no requirement of backlight, high contrast, ultra-thin, wide view angle, fast response, and applicability of flexible panel, wide range of working temperature, simpler structure and process. The OLED is considered as next generation flat panel display technology.
An OLED display generally comprises a substrate, an anode located on the substrate, an organic emitting layer located on the anodes, an electron transport layer located on the organic emitting layer, and a cathode located on the electron transport layer. As working, the Hole and the Electron from the cathode are injected to the organic emitting layer, these electrons and the holes are combined to generate excited electron-hole pairs, and the excited electron-hole pairs are converted from the excited state to the ground state for achieving illumination.
In the present production procedure of the flat panel display, the Mura (uneven brightness) often happens due to the reasons, such as the production processes, and a bright spot or a dark spot appears to lead to the display quality descend of the panel. For eliminating the Mura of the OLED display, the compensation table is generally employed to store the compensation information of the respective pixels in the OLED display in prior art. As showing images, the driver board looks up in the compensation table and adjusts the signals to raise the signal of the overdark zone of the panel and to lower the signal of the overbright zone for showing the uniform display result. In the compensation table, each pixel corresponds to one set of compensation information. Each set of compensation information comprises one or more compensation data. The physic meaning of the compensation data is determined according to the algorithm, which is the adjust value or the local gamma value of the specific gray scale in general. Alternatively, it is set to be the voltage value to be adjusted in some algorithm.
In prior art, the size of the compensation table is equal to the pixel amount plus the size of each set of the compensation information. However, not all the pixels in the OLED display need to be compensated. There are also a great amount of pixels which need no compensation. In the aforesaid storage method, the pixels which need no compensation also occupy the storage space. The storage space occupied by the compensation table is pixel column number*pixel row number*compensation information size*color amount. As an illustration, a 4K2K OLED panel needs to be compensated (the pixel column number is 3840, and the pixel row number is 2160), and supposing that size of each set of compensation information is 24 bit, and the color amount is three, the red, the green and the blue. Then, the storage space occupied by the compensation table is 2160*3840*24 bit*3:=597 Mb. The compensation table occupies a large system storage space, and consumes plenty of time for transmission and record of the data in the production line, which reduces the operation speed and the production efficiency of the OLED display panel.